A scheme is developed for classifying the types of motion perceived by a humanlike robot. It is assumed that the robot receives visual images of the scene using a perspective system model. Equations, theorems, concepts, clues, etc., relating the objects, their positions, and their motion to their images on the focal plane are presented. >

http://ieeexplore.ieee.org/iel2/815/3148/00100651.pdf

Robot vision

Continuum robotics has rapidly become a rich and diverse area of research, with many designs and applications demonstrated. Despite this diversity in form and purpose, there exists remarkable similarity in the fundamental simplified kinematic models that have been applied to continuum robots. However, this can easily be obscured, especially to a newcomer to the field, by the different applications, coordinate frame choices, and analytical formalisms employed. In this paper we review several modeling approaches in a common frame and notational convention, illustrating that for piecewise constant curvature, they produce identical results. This discussion elucidates what has been articulated in different ways by a number of researchers in the past several years, namely that constant-curvature kinematics can be considered as consisting of two separate submappings: one that is general and applies to all continuum robots, and another that is robot-specific. These mappings are then developed both for the single-section and for the multi-section case. Similarly, we discuss the decomposition of differential kinematics (the robotâ??s Jacobian) into robot-specific and robot-independent portions. The paper concludes with a perspective on several of the themes of current research that are shaping the future of continuum robotics.

/pdf/design-and-kinematic-modeling-of-constant-curvature-4wrx5stlzx.pdf

Design and Kinematic Modeling of Constant Curvature Continuum Robots: A Review

Newness and distinctiveness is claimed in the features of ornamentation as shown inside the broken line circle in the accompanying representation.

Display screen or portion thereof with graphical user interface

Traditional robots have rigid underlying structures that limit their ability to interact with their environment. For example, conventional robot manipulators have rigid links and can manipulate objects using only their specialised end effectors. These robots often encounter difficulties operating in unstructured and highly congested environments. A variety of animals and plants exhibit complex movement with soft structures devoid of rigid components. Muscular hydrostats e.g. octopus arms and elephant trunks are almost entirely composed of muscle and connective tissue and plant cells can change shape when pressurised by osmosis. Researchers have been inspired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments. This paper discusses the novel capabilities of soft robots, describes examples from nature that provide biological inspiration, surveys the state of the art and outlines existing challenges in soft robot design, modelling, fabrication and control.

/pdf/soft-robotics-biological-inspiration-state-of-the-art-and-1esuws0p9g.pdf

Soft robotics: Biological inspiration, state of the art, and future research

Medical Image Computing and Computer-Assisted Intervention

In this paper we present the clinical motivation, design specifications, kinematics, statics, and actuation compensation for a newly constructed telerobotic system for Minimally Invasive Surgery (MIS) of the throat. A hybrid dual-arm telesurgical slave, with 20 joint-space Degrees-of-Freedom (DoFs), is used in this telerobotic system to provide the necessary dexterity in deep surgical fields such as the throat. The telerobotic slave uses novel continuum robots that use multiple super-elastic backbones for actuation and structural integrity. We present the kinematics of the telesurgical slave and methods for actuation compensation to cancel the effects of backlash, friction, and flexibility of the actuation lines. A method for actuation compensation is presented in order to overcome uncertainties of modeling, friction, and backlash. This method uses a tiered hierarchy of two novel approaches of actuation compensation for remotely actuated snake-like robots. The tiered approach for actuation compensation uses compensation in both joint space and configuration space of the continuum robots. These hybrid actuation compensation schemes use intrinsic model information and external data through a recursive linear estimation algorithm and involve compensation using configuration space and joint space variables. Experimental results validate the ability of our integrated telemanipulation system through experiments of suturing and knot tying in confined spaces.

/pdf/design-and-integration-of-a-telerobotic-system-for-minimally-1u36ww14sl.pdf

Design and Integration of a Telerobotic System for Minimally Invasive Surgery of the Throat

This work presents a design overview of a novel high DoF (degrees-of-freedom) system being developed for minimally invasive surgery of the throat. The system is designed to allow remote operation of 2-3 tools with high tip dexterity to enable suturing and soft-tissue manipulation while using the patient's mouth as the only entry port. The slave is a 34 DoF unit equipped with three snake-like distal dexterity units for surgical tool manipulation. Each of these units is a multi-backbone snakelike mechanism equipped with a detachable milli parallel manipulator allowing interchangeable tools to be used. The paper presents the outline of the kinematic analysis of the snake-like units and proposes one possible actuation redundancy resolution to allow further downsize scalability while reducing the risk of buckling of the primary backbone of the snake-like units. Finally, The work presents a first early experiment with a prototype of the snake-like unit.

A dexterous system for laryngeal surgery

This paper presents the theoretical analysis and the experimental validation of the force sensing capabilities of continuum robots. These robots employ superelastic NiTi backbones and actuation redundancy. The paper uses screw theory to analyze the limitations and provide geometric interpretation to the sensible wrenches. The analysis is based on the singular value decomposition of the Jacobian mapping between the configuration space and the twist space of the end effector. The results show that the sensible wrenches belong to a 2-D screw system and the insensible wrenches belong to a 4-D screw system. The theory presented in this paper is validated through simulations and experiments. It is shown that the force sensing errors have an average of 0.34 g with a standard deviation of 0.83 g. Another experiment of generating the stiffness map of a silicone strip suggests possible medical application of palpation for tumor detection. The presented study allows force sensing in challenging environments where placing force sensors at the distal end of a robot is not possible due to limitations such as size and MRI compatibility.

An Investigation of the Intrinsic Force Sensing Capabilities of Continuum Robots

This paper presents a novel and unified analytic formulation for kinematics, statics, and shape restoration of multiple-backbone continuum robots. These robots achieve actuation redundancy by independently pulling and pushing three backbones to carry out a bending motion of two-degrees-of-freedom (DoF). A solution framework based on constraints of geometric compatibility and static equilibrium is derived using elliptic integrals. This framework allows the investigation of the effects of different external loads and actuation redundancy resolutions on the shape variations in these continuum robots. The simulation and experimental validation results show that these continuum robots bend into an exact circular shape for one particular actuation resolution. This provides a proof to the ubiquitously accepted circular-shape assumption in deriving kinematics for continuum robots. The shape variations due to various actuation redundancy resolutions are also investigated. The simulation results show that these continuum robots have the ability to redistribute loads among their backbones without introducing significant shape variations. A strategy for partially restoring the shape of the externally loaded continuum robots is proposed. The simulation results show that either the tip orientation or the tip position can be successfully restored.

/pdf/analytic-formulation-for-kinematics-statics-and-shape-awo8twmmnh.pdf

Analytic Formulation for Kinematics, Statics, and Shape Restoration of Multibackbone Continuum Robots Via Elliptic Integrals

Methods and systems are described for controlling movement of a continuum robot that includes a plurality of independently controlled segments along the length of the continuum robot. The continuum robot is inserted into a cavity of unknown dimensions or shape. A plurality of forces acting upon the continuum robot by the surrounding cavity are estimated. A positioning command indicating a desired movement of the distal end of the continuum robot is received from a manipulator control. The desired movement is augmented based, at least in part, on the estimated plurality of forces acting on the continuum robot such that movement is restricted to within safe boundaries of the surrounding cavity. The positioning of the continuum robot is then adjusted based on the augmented desired movement.

Nabil Simaan

Papers

Design and Integration of a Telerobotic System for Minimally Invasive Surgery of the Throat

A dexterous system for laryngeal surgery

An Investigation of the Intrinsic Force Sensing Capabilities of Continuum Robots

Analytic Formulation for Kinematics, Statics, and Shape Restoration of Multibackbone Continuum Robots Via Elliptic Integrals

Systems and methods for safe compliant insertion and hybrid force/motion telemanipulation of continuum robots